Photographic material for the silver dye bleaching process

ABSTRACT

Photographic material for the silver dyestuff bleaching process is provided which contains in at least one silver halide emulsion layer a bleachable azo dyestuff as image dyestuff and an asymmetrically substituted thiocarbocyanine as red sensitizer. Unexpectedly high relative sensitivities are achieved with these sensitizers which may have a betainelike structure, especially in the presence of polyazo dyestuffs.

Unite States ateii *t ruenggei' et al.

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PHOTQGRAPHIC MATERIAL FOR SILVER DYE BLEACHING PROCESS HeinrichBruengger, Basel; (Iarlo Boragine, Fribourg, both of Switzerland CIBAGeigy AG, Basel, Switzerland Aug. 21, 1969 Inventors:

Assignee:

Filed:

Appl. No.:

Foreign Application Priority Date Aug. 26, 1968 Switzerland ..1277l US.Cl ..96/99, 96/126, 96/137 3,157,507 11/1964 Bruengger et all ..96/993,255,0l2 6/1966 Glockner et al. ....96/106 X 3,348,949 10/1967 Bannertet al. ..96/106 Primary Examiner--Normal G. Torchin AssistantExaminer-John L. Goodrow Attorney-Harry Goldsmith, Joseph G. Kolodny andMario A. Monaco [5 7] ABSTRACT Photographic material for the silverdyestutf bleaching process is provided which contains in at least onesilver halide emulsion layer a bleachable azo dyestufi as image dyestuffand an asymmetrically substituted thiocarbocyanine as red sensitizer.Unexpectedly high relative sensitivities are achieved with thesesensitizers which may have a betainelike structure, especially in thepresence of polyazo dyestuffs.

10 Claims, No Drawings which may have a betainelike structure, in whichA represents a hydrogen atom or an alkyl group containing one to fourcarbon atoms; R, and R, each represents an alkyl group containing one tofour carbon atoms, an alkylcarboxylic acid residue containing one tofive carbon atoms, a sulfatoalkyl residue containing one to four carbonatoms or an alkylsulfonic. acid residue in which alkyl is a residue ofthe formula --C,,H,,,- n being a whole number from I to 4, and in whichan acid group B, or B, may have a betainelike structure; R, and R arcdissimilar aromatic ring systems which contain at most two sixmemberedrings and are fused on in the manner indicated by the valency lines; YQ.represents an anion and p=1 in the case of a betaineiike structure orp=2 when the molecular structure is not betainelike.

Betainelike structures result when at least one of the residues B, or Brepresents a sulfatoalkyl or an alkulsulfonic acid residue, or when B,and B each represents an alkylcarboxylic acid residue. In thebetainelike structure there is no anion Y because the anion is alreadypresent in the molecule of the sensitizer itself, that is to say islinked by a homopolar bond with the N-aikyl group of the sensitizer.This is also referred to as a zwitterion or an inner salt. When B, and Beach represents an alkyl group or one of them represents an alkyl groupand the other an alkylcarboxylic acid residue, the sensitizer does nothave a betainelike structure, and the anion Y neutralizes the positivecharge of the actual sensitizer molecule.

/S o I R, (Y ar-1 i R1 I C-CH:

in which A represents a hydrogen atom or an alkyl group containing oneto four carbon atoms; R represents an alkyl group containing one to fourcarbon atoms or an alkylcarboxylic acid residue containing one to fivecarbon atoms; 8., represents a sulfatoalkyl residue containing one tofour carbon atoms or an alkylsulfonic acid residue in which alkyl is aresidue of the formula -C,,H,,,- and n is a whole number from 1 to 4,preferably from 1 to 3; B, represents an alkyl group containing one tofour carbon atoms; R, and R represent dissimilar aromatic ring systemswhich contain at most two six-membered rings and are fusedon in themanner indicated by the valency lines; Y represents an anion and HF! or2.

A preferred photographic material contains a sensitizer not having abetainelike structure, corresponding to the formula in whichA, B B R,,R, and Y have the meanings defined above.

The residue A in the formulas (l) to (III) is in the so-calledmeso-position of the trimethine chain of the molecule; it is either ahydrogen atom or a methyl, propyl, butyl or especially an ethyl group.

The residues B, and B, are residues of the formulas (IV) --alkylene-H,(V) alkyleneCOOl-ll, (VI) alkyleneOSG l-l or (VII) alkylene-SO H,

in which alkylene stands for an alkylene group containing one to fourcarbonatoms.

As relevant examples the following residues may be mentioned; methyl,ethyl, propyl, isobutyl groups, acetic acid residues, propionic acidresidues, valeric acid residues, sulfatomethyl, sulfatoethyl,propylsult'onic acid or butylsulfonic acid residues.

Specially valuable in this connection are sensitizcrs of the formula(Vlll) S in which B, represents an ethyl, methylcarboxylic acid orethylcarboxylic acid residue, and A, R,, R and Y have the meaningsdefmedabove.

The residues R, and R- in the formulas (I) to (Ill) represent ringsystems fused on as indicated by the valency lines, which must always bedifferent from each other, have an aromatic character and contain atmost two six-membered rings. R, and R may be different from each otherinsofar as the type of the ring systems, the kind and number of thesubstituents in the same ring system or the positions of identicalsubstituents in the same ring system are concerned. R, and R mayrepresent the complements, for example, to the following residues:benzene or naphthalene residues, tetrahydronaphthalene residues orheterocyclic residues, for example coumarone, thionaphthene orbenzoar-pyrane residues. All these residues may, of course, carry a widevariety of substituents, for example halogen atoms, alkyl, aryl orheterocyclic residues, and these .alkyl or aryl residues or heterocyclicresidues may be bound to the ring system directly or through aheteroatom, for example and oxygen or a sulfur atom. Therefore, R, and R mayalso be, for example diphenyl, furylbenzene or thienylbenzene residues.

Very good results have been achieve-d with sensitizers of the formula inwhich R and R represent dissimilar benzene or naphthalene'residues,which are fused on in the manner indicated by the valency lines and maybe substituted by hydrogen atoms, halogen atoms, alkyl or alkoxy groupseach containing one to three carbon atoms, and A, B B and Y have theabove meanings.

Among these sensitizers those are preferred which correspond to theformula in which X X X and X each represents a hydrogen or halogen atom,or an alkyl or alkoxy group each containing one to three carbon atoms,and the substituent pair X,/X must differ from the substituent pair X /Xas to kind or position, and A, B B and Y have the above meanings.

The residues X and X are preferably in the 6- or 7-position or 6- or7'-position, and the residues X and X, are in the 5- are especiallyvaluable; in this formula A, B B X X X X and Y Q have the above meaningsand the substituent pair X IX is different from the substituent pair X/X Of very special value are the sensitizers of the formula in which X XX and X each represents a hydrogen or chlorine atom, or a methyl,methoxy or ethoxy group, and the substituent pair X t,/X must bedifferent from the substituent pair X-,/X,,, and A, B B and Y have theabove meanings.

l B3 WM...

The residue Y in the formulas (l) to (Ill) and (Vlll) to (Xll)represents one of the anions conventionally used in the chemistry of thecyanine dyestuffs, which as is known have a minor importance for thesensitizing effect (cf. F. M. Hamer, The Cyanine Dyes and RelatedCompounds, chapter 10, page 296). sensitizers containing preferredanions correspond to the formula (Xlll) \/s\ /s R. oon=oon=o R, m 1 n on7 5 nin which Y represents a halogen, thiocyanate, perchlorate, nitrate,methylsulfate, ethylsulfate or para-toluenesulfonate ion, and A, B B Rand R have the meanings indicated above.

Especially effective red sensitizers correspond to the formu- (XIV) x5\s\ CH s\ /X7 3 5 COH=( J-CH=C Y e/ x, 1 I X8 .39.. 2 s

in which Y B X X X, and X have the above meanings.

Suitable representatives of the red sensitizers according to formula (I)are, for example, the compounds shown in the following table in whichthere are listed in Column I the formula number Column ll the absorptionmaximum in mm, measured in ethanol Column lll the sensitizing maximum,measured in an exposed and developed silver halide gelatine emulsionRemarks:

The compound No. 13* in the table contains a benzene ring fused on inthe 4',5-position instead of the residue X,,. The compounds Nos. 32 to35 have additionally an l-l C residue in the 7-position. The compoundNo. 5 8" has additionally an H C residue in the 7 '-position. I Thecompound No. contains a benzene ring fused on in the 6,7'-position.

I X1 X, B1 A B, X1 X4 Y II III 58 3 H CH; ...do do Same as above H CH3I- 554 640 23:13:33: i} :55 ei f e'apooofi "1:383:33: gmfis above ii i222 238 61 -H -CH1 -CzH5 d -CIIg-CH2 CH -OC2H5 I 563 640 O OH 62 H -01Same as above do CH CH -H H 554 644 33111113111111: IE airi 'em em sm"3:383:11: $231251; above $151.... E5315. f. "523 233 PAT. NO. 3,635,716FOLIO 154 65 H -Cl C2II5 v do CHg-CH2 H 566 6 C O OH 66 -H --HCHz-Cl[zO-S 03 d0. CzH H -CH3 554 6 0 67 H OCH3 -C1H d0 -CHz-CH2 H Br558 650 Especially suitable red sensitizers of iii'fFrTuiHiS 562Ecompounds of the formulas 2, 6, 8, 35, 65 and especially 7, 10, l l, 20,43 and 60. From this it follows that compounds that carry on onenitrogen atom an ethyl group, on the other nitrogen atom apropylsulfonic acid or propionic acid residue, in meso-position an ethylgroup and on the nuclei chlorine atoms or methyl groups as substituentsare especially effective sensitizers in photographic materials for thesilver dye. bleaching process.

The cyanine dyes to be used according to this invention as redsensitizers in photographic material for the silver dye bleachingprocess are in part known or can be manufactured by known methods, forexample as described in the book of F. M. Hamer The Cyanine Dyes andRelated Compounds, chapters V and VII [lnterscience Publishers, NewYork, 1964]. Further manufacturing processes have been described, interalia, in German Pat. No. 917,330 and 929,080, French, Pat. No.1,166,246, Belgian Pat. No. 571,034 and in US. Pat. No. 2,503,776.

According to one suitable method of manufacturing the sensitizers of theformula (I), for example, a quaternary cycloammonium salt of the formula(XVa) S is condensed with a compound of the formula (XVII)photosensitive silver halide layer already contains a dye which absorbsexposinglight and thereby reduces the effective sensitivity of thelayer. The sensitizing of such dyed layers is rendered especiallydifficult by the fact that the dyes incorporated with the layer not onlyreduce the sensitivity by ab sorption but also have a strongdesensitizing effect on the emulsion.

According to this invention unexpectedly high relative sensitivities areachieved in sensitizing photographic layers for the silver dye bleachingprocess by adding a cyanine dye of the formula (I) as red sensitizer tothe silver salt emulsions containing an azo dye.

Particularly valuable sensitizers of the formula (I) are those which arecapable of forming the .l-band; they are distinguished by a verycharacteristic sensitivity bond with a steep drop towards the longerwavelengths and have, compared with the absorption maximum in analcoholic solution, a sensitizing maximum displaced bathochromically by70 to nm. This formation of a polymerization band, the so-called J-band,referred to as a sensitization of the second order, is technicallyvaluable not only insofar as the location of the sensitizing maximum isconcerned but also because of the relative sensitivities attained inthis manner.

The red sensitizers to be used according to this invention inphotographic material for the silver dye bleaching process have alreadybeen used as sensitizers in gelatine emulsions containing colorcouplers. These gelatine emulsions containing color couplers are used inthe manufacture of color photographs based on the principle ofchromogenic development. In such layers these sensitizers aredistinguished by the fact that their sensitizing effect is not, or atmost only very slightly, affected by the presence of the color coupler.Nevertheless, the fact that such sensitizers can also be used in layerscontaining azo dye for the silver dye bleaching process successfully wasunexpected and surprising. Thus, it is known that azo dyes are generallymore substantive in dyeing than the colorless components used ascouplers; this is especially true of polyazo dyes (to which practicallyall cyanazo dyes belong) which diminish the sensitizing capacity of thepreviously used sen- 'sitizers. Therefore, it should have been expectedthat in the layers containing an azo dye for use in the silver dyebleaching :process an adequate sensitizing efi'ect of the sensitizerupon the silver halide would not be achieved or would even be totallyinhibited. That is to say, it was to be expected that the azo dye coulddisplace the sensitizers adsorbed on the silver halide or that the dyewould form an inactive compound with athe sensitizer. Therefore, theextremely high increase in sen- ;sitivity achieved with the use of thesensitizers according to :this invention in the presence of azo dyes,especially polyazo dyes, was entirely unexpected,

7 9 lt is 51's; known th at azddyesare desensitizers and diminish thesensitivity achieved with conventional cyanine sensitizers.

The high sensitivity obtainable by the sensitizers to be used accordingto this invention is also found in layers containing; azo dyes that arefixed by precipitation with basic precipitants, for example biguanides;this is surprising because it is known that these basic precipitants(biguanides) act as descnsitizers so that it should have been expectedthat their presence in the emulsion would have an unfavorable effect onthe sensitivity.

Equally good results are obtained when azo dyes are used that containphenol groups. It has been known for a long time that azo dyescontaining phenol groups have a disturbing influence on the activity ofthe known sensitizers.

The present sensitizers can be used independently of the kind of silverhalide concerned. Apart from gelatine, other colloids can be used aslayer formers. Furthermore, the present sensitizers can be used not onlyin multilayer materialsbut also, for example, in mixed grain emulsions.The emulsions may further contain casting assistants of all kinds, forexample wetting agents, hardeners and/or stabilizers.

It is usual to incorporate the red sensitizers of formula (I) with alayer containing ableachable cyanazo dye.

The percentages shown in the following examples are percentages byweight.

EXAMPLE 1 Equal parts of a silver bromide-iodide emulsion containing 5 3g. of silver and 70 g. of gelatine per 1 kg. of emulsion are mixed at 40C. with different ethanolic solutions of sensitizers so that asensitizer concentration of 170 mg. per mol of silver results.

Emulsion sensitizer of formula A (2) B C (7) D (ID) E (l I) Forcomparison, emulsion F is prepared which contains a so-calledsymmetrical sensitizer which differs from the sensitizers of thisinvention.

Emulsion F: Sensitizer of the formula The solutions A to F are cast on atransparent film base so that the coating contains 3 g. of silver per111. The castings are subjected to sensitometric exposure behind a greywedge and a yellow filter and then developed as follows:

1. Development for 6 minutes in a bath that contains per liter of water50 g. of anhydrous sodium sulfate, 0.2 g. of l- (XVII)phenyl-B-pyrazolidone, 6 g. of hydroquinone, 35 g. of an-' hydroussodium carbonate, 4 g. of potassium bromide and 0.3 g. of benztriazole;

2. washing for 5 minutes, then fixing for 6 minutes in a solution of 200g. of crystalline sodium thiosulfate and 20 g. of potassiummeta-bisulfite in 1 liter of water and washing for another 5 minutes;

3. color-bleaching for 3 to 12 minutes with a solution which containsper liter of water 50 to g. of potassium bromide, 40 to 80 g. ofthiourea, 35 to 80 g. of 30 percent sulfuric acid and 0.0] g. of2-amino-3-hydroxyphenazine;

4. washing for 10 minutes;

5. bleaching of residual silver for 5 minutes with a solution of 60 g.of crystalline copper sulfate, 80 g. of potassium bromide and 15 ml. of30 percent hydrochloric acid per liter of water, and

6. washing, fixing and again washing as described under 2.

The unexposed castings of emulsions A to F are also exposed spectrallyin a spectrosensitometer. Processing is as described above under 1 and2, that is to say only a blackwhite development is carried out.

The results are summarized in the following table. The smaller value ofthe relative sensitivity log E indicates a higher sensitivity.

The sensitizers used according to this invention in emulsions A to Eproduce a higher sensitivity and displace the sensitivity maximumtowards longer wavelengths than does the symmetrical control sensitizerincorporated in emulsion F. For a redsensitive emulsion in a colorphotographic material a sensitization with a maximum of 600 nm. orhigher is generally required, and preferably it is within the range from640 to 700 nm.

EXAMPLE 2 Equal parts of a silver bromide-iodide emulsion of mediumsensitivity, containing 21 g. of silver and g. of gelatine per 1 kg. ofemulsion, are mixed at 40 C. with different ethanolic solutions ofsensitizers so that a sensitizing concentration of I50 mg. per mol ofsilver results.

Emulsion sensitizer of the fonnula A according to the invention (2) 8according to the invention (6) C according to the invention D forcomparison (XVI) To emulsions A to D there are then added theconventional additives, e.g. stabilizers, wetting agents, softeningagents and hardeners, as well as an aqueous solution of the cyan dye ofthe formula (XVIII) in an amount such that a dye concentration iusllsstef s s esu ts;

The solutions A to D are cast over a white opaque base to is used in aconcentration of 3.6 g. per I kg. of emulsion. produce a coatingcontaining 1.9 g. of silver per m.. The sensitizers of the formulas (6),(l) and (l I) produce The coated material is subjected to spectralexposure under similarly improved relative sensitivities andsensitization mux a spectrosensitometer and developed as described underl and ima shifted towards longer waves as shown in example 3. 2 inexample 1. The sensitization maxima thus achieved are as 5 follows:EXAMPLE 5 Sensitization maximum The procedure is as described in example2, except that the Emulsion in nm.

following sensitizers are used in a concentration of 150 mg. of Aaccording to the invention 640 Sensltwer per mol of sllver: B accordingto the invention 630 C lccoldinfl invention Emulsion Sensitizer offonnula D for comparison 7 600 g B (2) The sensitization maxima that canbe obtained with the senc (7) sitizers according to this invention arefound at higher 3 238 wavelengths than can be obtained with thesensitizer 'used for comparison.

EXAMPLE 3 (XX) S c H S The procedure is as described in example 2,except that the 2 5 e C-CH=CCH=C I following sensitizers are used:

Sensltlzer mg. of sensitizer \g/ \N/ of the per mol of Hmulslon formulasilver $2 6 i w A a g 250 y a 10 250 Th d d h d f C (H) 50 e lmage yeuse is t e ye o the formula (XIX) In an o (XVI) 150 amount such that adye concentration of 3.6 g. per kg. of emulsion results.

The emulsion is cast as described in example 2, and then The amounts ofsensitizer have been chosen so that a maxspectrally exposed anddeveloped as described in example 1. m s itivit is chieved, Thefollowing sensitization maxima are found:

The emulsions are cast as described in example 2, then exposed under aspectrosensitometer and developed as Sensitization maximum described inexample 1. Emulm" The results obtained are shown in the following table:

. A according to the invention 635 mack'whm development B according tothe invention 640 Emu sion color f'f 'f 40 C according to the invention642 according rel. sensitivity D for compafiwn 590 to the I I E E forcomparison 600 invent1on rel. sensitlsensitivity vity log E maximum inI'IITI.

' Compared with the control sensitizers the sensitizers to be A 1.90 6303.47 used according to this invention display a distinct shift of the B139 640 sensitization maximum. c 1.11 650 2.74 D for comparison '2. 15600 3.76 EXAMPLE 6 The procedure is as described in example 1, exceptthat a concentration of 200 mg. of sensitizer per mol of silver is usedA comparison of th m I H A C Wlth D reveals a and a coating containing1.6 g. of silver per m. is produced distinct gain in sensitivity and ashift of the sensitization maxi h h f llowing i i imum towards longerwaves in the case of the sensitizers to be used according to thisinvention compared with the sensitizer 1 compared Emulsion sensitizer offormula EXAMPLE 4 A as The procedure is as described in example 3,except that in- B 60 stead of the cyan dye of the formula (XVIII) thedye of the C formul w H D Xx (XIX) 01 For comparison emulsion D isprepared which contains a so-called symmetrical sensitizer that isdifferent from the sen-' 004m OH sitizers to be used according to thisinvention.

N=N. (XXI) C H no s- -s03n 2 5 C-CH:( J-CH=C I9 OCH; HO mew-05H" N 111 NN (12m camera-c0011 0 CH3 H03 S The results are shown in the followingtable:

Color development 1 Spectrum sensitivity relative sensitivity lEmulsionmaximum in nm. log E D 645 Mil A comparison of emulsions A to C with Dreveals a distinct gain in sensitivity 1 and a shift of thesensitization maximum towards longer waves in the case of thesensitizers to be used according to the invention as against thesensitizer compared.

EXAMPLE 7 The procedure is as described in example I, except that aconcentration of 200 mg. of sensitizer per mol of silver is used and acoating containing 1.6 g. of silver per m. is produced with thefollowing sensitizers:

Emulsion Sensitizer of formula G 65 H XXI for comparison The image dyeused is the dye of the formula (XVlll) in an amount such that a dyeconcentration of 19.5 g. per 1 kg. of emulsion results.

The results are listed in the following-table:

Color development Spectrum sensitivity relative sensitivity Emulsionmaximum in nm. log E A 640 3.56 B 645 3.28 C 650 3.89 D 650 4.55 E 6453.33 F 650 4.55 G 655 3.52 H 5 8O faint image not detenninable Acomparison of emulsions A to G with H reveals a distinct gain insensitivity and a shift of the sensitization maximum towards longerwaves in the case of the sensitizers to be used according to thisinvention as against the sensitizer compared.

EXAMPLE 8 The procedure is as described in example 2, except that aconcentration of 200 mg. of sensitizer per mol of silver is used and acoating is produced, which contains 1.5 g. of silver per m with thefollowing sensitizers:

Emulsion sensitizer of formula XX for comparison The image dye used isthe dye of the formula (XVll) in an A comparison of emulsions A to Gwith H reveals a distinct gain in sensitivity and, in some cases, ashift of the sensitization'maximum towards longer waves in the case ofthe sensitizers to be used according to this invention as against thesensitizer compared.

EXAMPLE 9 The procedure is as described in example 2, except that aconcentration of 200 mg. of sensitizer per mol of silver is used and acoating containing 1.5 g. of silver per m is produced with the followingsensitizers:

Emulsion Sensitizer of formula A B B 20 C 35 D 43 F 62 G 65 H XXI forcomparison The results are listed in the following table:

Color development Spectrum sensitivity relative sensitivity Emulsionmaximum in nm. log E H 575 faint image not determinable A comparison ofemulsions A to G with H reveals a distinct gain in sensitivity and ashift of the sensitization maximum towards longer waves in the case ofthe sensitizers to be used according to this invention as against thesensitizer compared.

EXAMPLE 10 The procedure is as described in example 2, except that aconcentration of 200 mg. of sensitizer per mol of silver is used and acoating containing 1.5 g. of silver per m? is produced with thefollowing sensitizers:

Emulsion sensitizer of formula A 35 8 6 11 C 65 D XXII 1 For comparisonemulsion D is prepared; it contains a so- ;called symmetrical sensitizerthat is different from the senamount such that a dye concentration of2.6 g. per 1 kg. of sitizers to be used according to this invention andcorresponds lemulsion results.

.tqthatsr su ac l5 l6 (XXll) S S i in which R and R are differentbenzene or naphthalene radi- C2115 cals WhlCh are fused on in the mannerindicated by the valency C C 1125* 011: 9 lines and are substituted byhydrogen or halogen atoms or by m alkyl or alkoxy groups each containingone to three carbon \Q atoms.

5. A photographic material as claimed in claim I. which e contains a redsensitizer of the formula The results are shown in the following table:m s

i 1/ Color development e Spectrum lemltivlty relative ,senlitivityCCH=CCH=C 1 Emulsion 7 maximum in nm. log E X1 w A 645 2.8] B3 B5 I a645 2.1m 1 5 C in whichX x x ax h' hd D 640 v 1" a an 4 eac 1s a y rogenor halogen atom, or an alkyl or alkoxy group each containing one tothree carbon atoms, and in which the substituent pair X IX, differs fromthe substituent pair X,/X as to type or position.

6. A photographic material as claimed in claim 5, which contains a redsensitizer of the formula A comparison of emulsions A to C with Dreveals a distinct gain in sensitivity and a shift of the sensitizationmaximum towards longer waves in the case of the sensitizers to be usedaccording to the invention as against the sensitizer compared. S S X;

We claim: A l. A photographic material which contains a red sensitizer 1OH=C e of the formula e/ A S l i 6 B3 B5 R; l C-CH=CCH=C I R; Y

i vin which the substituent pair X IX, differs from the substituent Npair X /X 7. A photographic material as claimed in claim 5, which Mcontains a red sensitizer of the formula in which A is an alkyl groupcontaining one to four carbon S S atoms; 8;, and B independently are analkyl group containing X A one to four carbon atoms or analkylcarboxylic acid group 9 containing one to five carbon atoms,provided that both B X6 and B5 are not simultaneously alkylcarboxylicacid groups, RI \g N/ and R are different aromatic ring systems fused onin the i I manner indicated by valency lines and containing at most 40B5 1W0 six"membel'ed i t is f 1 in which X X X and X each represents ahydrogen or A Photograph!c mammal as claimed m whch chlorine atom or amethyl, methoxy or ethoxy group, and the Contains a red sensitizer ofthe formula substituent pair XJX, differs from the substituent pair X /X8. A photographic material as claimed in claim 7, which i s contains ared sensitizer of the fonnula m, s s in CC1-I=JJ--UI[---( 1 R, Y Xv our,

e/ CCH=CCH=C Y N Xu- I I I N N B3 B5 i boxylic acid radical.

3. A photographic material as claimed in claim 1, which contains a redsensitizer qfthe formula l 9. A photographic material as claimed inclaim 1, which contains the red sensitizer of the formula Ba BECK! v onofi ooon cam in which B, represents an ethyl, methylcarboxyli'c orethylcarv 10. A photographic material as claimed in claim 1, which 4. Aphotographic material as claimed in claim 1, which contams the redSensmzer ofthe formula contains a red sensitizer of the formula 5 Q Re ic-olhi-cn o R4 Y CA1- \N f s v l B5 a a a a m

2. A photographic material as claimed in claim 1, which contains a redsensitizer of the formula
 3. A photographic material as claimed in claim1, which contains a red sensitizer of the formula
 4. A photographicmaterial as claimed in claim 1, which contains a red sensitizer of theformula
 5. A photographic material as claimed in claim 1, which containsa red sensitizer of the formula
 6. A photographic material as claimed inclaim 5, which contains a red sensitizer of the formula
 7. Aphotographic material as claimed in claim 5, which contains a redsensitizer of the formula
 8. A photographic material as claimed in claim7, which contains a red sensitizer of the formula
 9. A photographicmaterial as claimed in claim 1, which contains the red sensitizer of theformula
 10. A photographic material as claimed in claim 1, whichcontains the red sensitizer of the formula